Shower water runs cold

[jimus7]

I have a thermostatic mixer shower. This supplied by hot water and cold water from tanks on a traditional system. Both tanks are in the loft as is the boiler. The hot and cold are also on a 2.1bar pump, also in the loft.

The problem is the shower water is not hot - at best lukewarm.

I have tried the following:
- turned the shower thermostat to its highest.
- changed cartridge from manufacturer twice and whole shower once. the old cartidges did not appear to have defects.
- had the hot water on for several hours before use.
- ran shower for considerable amount of time.

The water from the same source runs hot on the bath and basin taps.

The shower was hot at when first installed.

Help!?!!

 

[Burnerman]

Do you get similar pressures with the shower set to fully cold, then fully hot?
John

 

[picasso]

do you have air vents fitted to the pump pipework at the highest point ?

 

[jimus7]

john - yes pressure is the same when on fully hot and full cold. There is a very slight temperature differential.

Picasso - to be honest i don't know about the air vents. However it looks like the pump has been put into the system about 4metres away from the tanks, just before the pipes go down to the house.

 

[seco services]

is the pipe to the rear of the shower hot/warm when shower running ?

what mixer is it ?

 

[jimus7]

the pipes have been boxed in behind the shower, although the one that feeds it can be felt hot when leaving the loft going down.

The shower is morretti from screwfix.

 

[seco services]

The shower is morretti from screwfix.

say no more.

have a read. MORETTI

 

[jimus7]

Hmmm.... I see your point. Thanks I will investigate with screwfix!